No, this isn’t a dice table of a hundred games, sorry. Instead it’s just four freely available ones that I think are, criminally, flying under everyone’s radar. And I’m here to scream about them from the rooftops.
I wanted to compile this because I’ve had many chats with would-be indie developers and hobbyist writers who believe making anything percentile based requires building off Chaosium’s Basic Role Playing or some variant thereof. There’s also a tendency to view all percentile systems as having massive catalogs of skills and character sheets that span pages. The good news is: this isn’t the case! There are plenty of d100-based games that take one of the easiest to grasp mechanics and applies it to relatively modest frameworks.
These four titles are choice picks I’ve stumbled across in the past couple years. They’re all freely available, allow you to use them to hack into your own projects, and each one has stuck with me for a different reason or another.
A complete, barebones percentile system in one page! (Well, front and back). It pretty much captures a distillation of gameplay and gimmicks I absolutely enjoy. One stand out to me: it’s all skills, no stats!
Character Creation is essentially taking an array of scores (ranging 60%-30%) and assigning them between a list of Basic ( base+15% for everyone) or Advanced skills. The game comes with premade skill lists for Fantasy, Modern and Sci-Fi settings. Wouldn’t be hard to build your own as you see fit or create new ones on the fly.
The gameplay mechanics are pretty straightforward — roll under your skill value when an action calls for it. GM may arbitrate -20% on difficult tasks. Rolling doubles means a critical result. All characters have 2 Focus Points they can spend to reroll, reduce damage or gain an extra action. Character advancement is simply if you fail a skill roll during play, that skill will gain +1% after the adventure.
Combat has a damage system where weapons are rated on how you read your roll — a Low-rated attack will look at the lowest die on your action, High your highest, and Total is the sum of both dice combined. Folks who remembered the playtest of Sigil & Shadow may remember a similar approach!
It’s short, it’s barebones, but it works. There’s a couple things I would tweak or add-on, but that’s the whole point — released for free under CC-BY-SA, it’s meant for you to swiftly hack into that setting you’ve been dying to run.
Hack100 is another generic game coming in at 32 pages. Has a really nice, clean and legible layout. Definitely feels inspired by classic percentile systems (a healthy mix of Chaosium and Warhammer influences on its sleeve). Instead of tracking a massive catalog of skills, characters consist of a Background, a Motivation, 10 broad abilities and maybe one “Specialism” — these are sort of a free-form approach to any specific talent or training a character may have. It can be skills like Medicine, IT, Theology, Languages, Pickpocketing, Occultism or whatever. Powers are fantastic abilities — spellcasting, shapeshifting, or going “berserk” are examples given. These let you do awesome things but at the detriment of losing health points.
The usual flavor of percentile gimmicks I love are present — especially crits on doubles, and using opposed rolls where contestants need to succeed and roll higher than their opponent. One mechanic prominent in this system is the Ability Score Bonus, which is essentially the “tens place” of an ability score (A stat of 32 has a bonus of +3, for example). This gets applied to things like damage and initiative rolls.
The core booklet supplies guidelines and optional rules for building NPCs, designing powers, allowing non-human characters and tacking on things like Advantage/Disadvantage or Luck Points. On the download page you can also pickup CRARG (Cataching Rats and Robbing Graves), a “grimdark” fantasy add-on with additional content to give you ideas at its implementation.
Speaking of grim dark, A Grim Hack is another CC-licensed d100 system you can pick up that wears its influences on its sleeve. Only this title outright steers hard into the “(totally not) Warhammer” vibe. It’s quite a bit more fleshed out and traditional with characters composed of stats, traits, skills, ancestries, occupations and what not. Still a pretty distilled and easy to get-to-table than its inspirations. There’s quite a bit of starter occupations and their trappings, as well as some interesting advanced occupations to progress into later.
Again, another flavor of roll-under percentile mechanics at its core. Has the “Advantage/Disadvantage” mechanic to flip dice; criticals rolled on doubles. There’s difficulty modifiers ranging from -30 to +30%.
The unique mechanic going on here is the Check Points, which is used to determine a degree of success to the rolls. In short: you take the tens-place die of your roll and subtract it from the value you were rolling against to determine your CP value. Example: rolling a 23 under a 65 means you score a CP of 4 (6-2). 0-1 CP is treated as a “narrow success” (or a success at cost/with consequence) while 4+ is considered a “sound success” performed effortlessly. This degree of success comes into play throughout various actions, but is mentioned explicitly when it comes to tasks where time is of the essence (such as casting invocations and rituals). These tasks have Threshold to beat, else success means they go on longer than desired.
Speaking of, the Magic in this system is flavorful in that perilous “low-fantasy” sort of way. It’s time consuming, consisting of rites and study to perform. It’s more of the folksy, thaumaturgical style than wizards cracking lightning from their fingertips. It’s also dangerous, as greater invocations require greater expenditures. There’s a really cool mishap table tucked away in there.
In addition to the core rulebook, there’s also a few different bestiaries of NPCs and beasts both basic and fabled. There’s also a starter adventure included in the mix — overall, Grim Hack is a pretty complete game. I think folks who are looking for something a bit meatier in the indie space wanting to catch all the vibes of Warhammer Fantasy, but without bogging down play, could do no wrong going with Grim Hack.
Another focused game, this one designed as a “rules lite ancient world fantasy”. In other words: it has a very hard Glorantha vibe to it. It’s bronze aged fantasy with an emphasis on community building and it has runes in it. But this isn’t an offshoot of RuneQuest! Of all the games I list here today, this may be the mightiest departure of trad percentile games. Folks who think d100 systems can’t work for more narrative/story-gamey play styles should read this subversion and have their minds blown.
Character creation is assigning an array of stats across 10 broad skills, choosing a career (like philosopher, shaman, priest, farmer, outcast and more.) Write down a Passion, select two Runes related to the god you worship, and you’re ready to adventure.
Gameplay is not what you expect. It’s Player-facing rolls. Actions that the player rolls for is the standard roll-under a skill to succeed. The interesting factor here is, in addition to checking for success, the player will then assign the dice rolled to either Damage or Fate. If successful, the Damage die is inflicted on the opponent or obstacle. Failure means that’s the damage taken to the character. Regardless of success or failure, the other die is assigned to the Fate table, which determines the flow of the story. 1-3, things get worse. 4-7, things stay the same; 8+ and things get better.
The GM will spend their time tracking the adventure progress and goings-on in the world. They will have a sheet to track their home community (which the campaign centers on). The campaign is actually broken up into seasons (in which the GM has a booklet for each). Each season has a myriad of adventure hooks, world building prompts, and quick NPC tools.